Automatic initialization in a model railroad motor control system

ABSTRACT

Electronic control circuits for model railroading including a reversing motor control circuit. An on-board electronic state machine indicates one at a time of a predetermined series of states including forward, neutral and reverse, and is clocked to the next state responsive to an interrupt in the track power signal. The circuit further includes reset means for resetting the state machine directly to a neutral state responsive to an interruption of the track power signal of extended duration. The state machine can be remotely programmed to reset to any desired one of the series of states in response to a track power signal interrupt. The unique reset state is useful for receiving various remote control signals without driving the motor.

This is a division of application Ser. No. 07/480,078, filed Feb. 14,1990, U.S. Pat. No. 5,184,048, which is a division of U.S. Ser. No.07/37,721, filed Apr. 13, 1987, now U.S. Pat. No. 4,914,431, which is acontinuation-in-part of U.S. Ser. No. 06/672,397, filed Nov. 16, 1984,now abandoned.

FIELD OF THE INVENTION

This invention relates to an electronic control system and in particularto the remote control of features and functions on AC powered modelrailroad locomotives.

BACKGROUND OF THE INVENTION

Ever since the beginning of model railroading the user has desired moreand more control over the operation of his model trains. The firstelectric model railroad locomotives had only a single remotefeature--the engine was either on or it was off. Later variable powerwas added and the operator could then also control the speed of hismodel trains. This was a definite advantage but still somewhat limitingsince the operator could not back the train up. The Lionel company firstintroduced a slide switch on the engine that could be thrown by handthat would reverse the engine and later introduced an innovativeelectrical-mechanical on-board (in the engine) motor control unit thatwould change the engine's direction by simply interrupting the appliedAC track power. This unit was later improved by adding a neutral stateto allow the train to stand idle when track voltage was applied. Thismotor control unit had a state sequence that moved from "forward" to"neutral" to "reverse" to "neutral" to "forward" etc. each time the ACpower was interrupted. The motor control unit is often referred to as a"reverse unit" or "E unit".

Today most model train engines are equipped with DC motors and theremote control of the trains direction is accomplished by applyingeither positive or negative DC power to the track. However, when Lioneldeveloped their reverse switch it was difficult to produce DC power andgood DC motors were not available. To this day the Lionel company usesAC power with the same basic electrical-mechanical motor control unitdesign.

The Lionel company also introduced an innovative remote control conceptfor their on-board whistle. Here a DC voltage of either polarity appliedto the track would actuate a DC receiver in the engine that in turnconnected track power to the whistle sound device allowing the operatorto blow the whistle when the engine was standing idle or moving, all byremote control.

No manufacturer of miniature AC powered trains has ever taken advantageof the fact that both polarities of DC voltage were available. However,model railroad enthusiasts soon discovered that judicious placement ofdiodes in the engine would allow them to control two trains on the sametrack independently or to expand their remote control options to two ona single engine.

Model railroaders that used DC track voltage did not have independentremote control options since the two DC polarities were already used tocontrol train direction. Only dependent options were available such as areverse headlight coming on when the train was moving in reverse.

Another capability that the model railroad enthusiast would like is away to move engines independently on the same track so that multipleunit consists (more than one engine operating in a single train) couldbe constructed or taken down in the model railroad yard or a pusherengine brought up to aid a train stranded on a grade. For the operatorthat uses DC track voltage, it is difficult to couple a moving engine toa stationary engine that occupies the same section of electrified tracksince both engines would respond to the same applied voltage. For theoperator that uses AC track voltage where each engine is equipped with amotor control unit, it is possible to couple a moving engine to astationary engine since the stationary engine could be in a neutralstate. However, once coupled, the two engines would remain out of sync.since each attempt to change the state of one motor control unit wouldalso change the state of the other.

Over the last ten to fifteen years a number of electronic controlsystems have been developed that attempt to solve one or both of theproblems of independent train control and expanded remote controlability. One approach is called command control and usestransmitter/receiver techniques to address single engines at a time.With this technique, each engine is equipped with a receiver that isspecifically coded or tuned to receive only one of a number oftransmissions that are being sent down the track. In this way eachoperator equipped with a transmitter can move his engine independentlyof other operators that have engines on the same section of electrifiedtrack. One disadvantage of these control systems has been that only asmall number of codes or train addresses are practical for a givensystem which means that additional engines over this number will begiven codes that are already used.

Some of these systems also have remote control options where an operatorcan turn on a bell or light on his engine independent of otheroperators. Most of these command control systems have a means ofcontrolling slaving engines together so that multiple unit consists canbe made up.

For the operator of AC train equipped with a motor control unit, thesolution for multiple unit consists was a little less complicated. Inone instance an electronic motor control unit was developed thatperformed the same function as the original motor control unit but wouldreset to a specified state if the power was off for more then aspecified period (in this case it was about twenty seconds). This way iftwo or more engines were out of sync. the entire consist could be shutdown for eight seconds and once power was restored all engines would bein the same state.

Although this motor control unit solved the problem of multiple unitoperation it did nothing for expanding the remote control options.

One application of this invention is to increase the number of remotecontrol options of AC powered electric trains where the locomotivescontain on-board reversing units. The motor control units are generallysequenced through their states by interrupting the AC power. The motorcontrol unit used in Lionel trains have four distinct states: 1) forward2) neutral before reverse 3) reverse and 4) neutral before forward. Forremote control, the Lionel company used a DC remote control voltage fortheir on-board whistle sound effect generator. For this case thepolarity did not matter since either a positive or negative DC voltagewould turn on the whistle. Although, this is a very limited electrictrain control system, it has been around for some time and mostoperators of Lionel trains are very comfortable with it. They tend toresist using complicated digital remote control systems for a variety ofreasons. First they are used to using the simple power interrupt tochange the direction of their locomotives--there is a quality ofdelightful simplicity in this. They also do not want to alter theirengines to the point where they would not work on other peoples trainlayout that use original Lionel transformers etc. However, there is somedissatisfaction with the limited number of remote options that areavailable and some operators have used both positive and negative DCvoltages to at least increase the number of remote control features totwo.

Adding the additional DC remote control voltage is about as complex aremote signaling system as most Lionel train operators want to go. Thechallenge for a new AC remote control system is to increase the numberof remote options and not change the basic simple and universaloperation of the old Lionel control system that has been around for thelast fifty years or so.

SUMMARY OF THE INVENTION

In accordance with the present invention a control system has beendeveloped for AC powered trains that uses the state of the motor controlunit along with any remote control signals available to the system toactuate a number of remote on-board features. On-board means it isattached to the remote object (a miniature locomotive in this case) thatis addressed by the remote control signals.

The object of this invention is to increase the number of remote controlfunctions from that which would normally correspond to the number ofcontrol signals available on an electronic control system by using anon-board electronic state generator (104) along with a combination logicblock (108) to select groups of operating effects where a particulareffect within each group can then be selected and/or operated by thelimited number of remote control signals that are available to thesystem.

In other words, each state of the on-board generator corresponds to adifferent group of remote control options that can each be selectedand/or operated by the remote control signals. If the on-board stategenerator has "n" stages that select groups of "m" effects each that canin turn be selected and/or operated by the remote control signals, thenthere are "n×m" (n times m) total remote control options available to beoperated by the remote control signals. The on-board state generator hasmade it possible to increase the number of remote control functions thatwould be available from the remote control signals alone.

A feature of this invention is to allow the user to choose the remotecontrol features that he would like to use by connecting the desiredeffect generator (i.e. horn, bell, etc.) into the combination logicblock. In other words, if he wants to select remote option "a" or "b"when the on-board state generator is in state "c" he need only connectthis option module to desired output from the combination logic block(108) where signal "c" will enable the two effects, "a" and "b" signalsto either affect "a" or "b" separately). This gives him a great deal oflatitude in choice of options and also allows him to change options at alater time without having to also change the on-board state generator orthe combination logic block (108.).

Another feature of this invention is to establish a preferred set ofsignals between the on-board state generator and the various optionsmodules.

The foregoing and other objects, features and advantages of theinvention will become more readily apparent from the following detaileddescription of a preferred embodiment which proceeds with reference tothe drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a general system block diagram;

FIG. 2A is a truth table relating output logic values Q1,Q2 of the motorcontrol units of FIG. 3 and FIG. 4 as they define four motor controlstates;

FIG. 2B is a state diagram illustrating transitions among the motorcontrol states of FIG. 2A.

FIG. 3 is a schematic electrical drawing of the electronic motor controlunit used for AC motors in one embodiment of the invention;

FIG. 4 is a schematic electrical drawing of the electronic motor controlunit used for DC motors in one embodiment of the invention;

FIG. 5 is block diagram of the on-board state generator and electronicmotor control unit used in one embodiment of the invention;

FIG. 6 is a schematic electrical drawing of the DC remote control signaldetector used in one embodiment of this invention;

FIG. 7 is a schematic electrical drawing of the DC signal generator usedin one embodiment of this invention;

FIG. 8 is a table listing the model train diesel engine remote controloptions used in one embodiment of this invention;

FIG. 9 is a table listing the model train steam engine remote controloptions used in another embodiment of this invention;

FIG. 10 is a block diagram showing a horn sound generator;

FIG. 11 is a block diagram showing an electrical latch used to rememberthe momentary presence of one of the remote control signals; and

FIG. 12 is a block diagram showing how the diesel engine options listedin FIG. 8 is electrically implemented.

FIG. 13 is a block diagram showing select signal generation using ACpower in excess of a predetermined value.

FIG. 14 is a block diagram showing coil uncoupler remote control latchand operation circuitry.

FIG. 15 is a block diagram of the preferred embodiment.

FIG. 16 is a perspective view of a model train system having a trackcoupled to an interruptible electric power source for providing a trackpower signal.

DESCRIPTION OF THE INVENTION

FIG. 1 shows the most general case. Here the state of the remote objectis indicated by the box 100 labeled "remote object state". The state ofa remote object is defined as any aspect of the object that can bedistinguished as different. In other words, its temperature, size, mass,velocity, age etc. could be descriptors of its state. Of the "k+p+r+q"total remote control lines 101 available to the system, "k" lines 102are reserved for changing the state of the remote object. A box 103labeled "other inputs to the remote object" are included to indicatethat the state of the remote object may not be precisely determined bythe "k" remote control lines 102. For instance, the temperature of theremote object may be used to change its state. The added on-boardelectronic state generator 104 is shown receiving inputs from the stateof the remote object 100, internal programming 105, "p" lines 115 of theavailable remote control signals and a box 106 labeled "other inputs tothe on-board electronic state generator". In other words, the state ofthe on-board electronic state generator can be determined from a varietyof inputs and only has as a limiting case the same state as the remoteobject.

The on-board state generator will have only one state at a time. Eachstate will enable signal gating in the combination logic block, 108, toselect and/or operate "m" remote control options for each of the "n"operating state signals 109. This has multiplied the number of remotecontrol options that would be available from the "m" effect controlsignals, 107, by the total number of states "n" of the on-boardelectronic state generator. In other words, each time the state of theon-board state generator changes it will enable another set of "m"different remote control effects to be actuated by the same "m" effectcontrol signals.

The state generator could, in principle, have an indefinite number ofstates limited only by the on-board electronics. In reality, however, itwould most likely cycle through a finite number of states to allow theoperator to revisit remote control options that have already beenaddressed.

The "m" effect control signals can either select each of the "m" effectsin a group or they can both select and operate each of the "m" effects.If the "m" effect control signals simply select the different effects,then "q" additional signals are provided for operating the selectedeffects. For this configuration, there are a possible (n×m×q) differentchoices since different effect operating signals could have differentaffects on each of the (n×m) effects.

The box, 110, is used to generate the "m" effect control signals fromthe "r" detected remote control signals. If there are enough remotecontrol signals available to the system, the "r" lines could be useddirectly as effect control signals. However, if there are limited remotecontrol signals, 110 can be used to generate additional signals toselect the different available "m" effects from the "r" remote controlsignals. For instance, the select state generator, 110, could simplycount the number of times that a particular remote control signal, r1,is applied in a given amount of time and generate one of the effectcontrol signals corresponding to this count. If 110 receives fiveapplications of r1, then the fifth effect control signal is activated.For our train control systems, where there may only be two DC remotecontrol signals available, it's important to increase the number ofeffect control signals. The signal, 120, from the on-board stategenerator can be used to alter how the select generator interprets the"r" select signals.

One of the nxm effects, 111, could be used to enable address and commandstorage, 119, to be activated. This allows unique addresses and commandsto be received from some combination of the remote control linesr+q+k+p, 131, through combination logic block, 108, and stored in memorylocated in 119.

For stored commands, the output of 119 through control signals 132, cancontrol how some of the n×m effects are programmed to respond to the "n"operating state signals and the "q" effect operating signals, and the"m" effect control signals. In this way, the remote object can learn orbe programmed by the user in any of a number of ways.

Another of the n×m effects, 111, can be used to enable 119 to receiveand store unique addresses from the incoming remote control lines.Thereafter, effect, 112 is used to enable 119 to receive addressinformation from 131 and compare it to the previously stored addresses.Depending on whether there is a match or not, 119 can, in turn, controlhow the m effect control signals, and q effect operating signals areinterpreted by the combination logic block 108 through signals 132. Inaddition, 119, can through signal 117 and signal gating block, 118,control the incoming r+q+p+k remote control signals. The idea ofprogramming separate address and commands for each locomotive is new tomodel railroading.

The box 114 labeled "signal detector" is used to change the incomingremote control signals, k+p+r+q to signals that can be used by thesystem. For instance, it may detect an incoming fifty kilohertz signaland produce a five volt DC logic signal that can be used by C-MOS ANDgates in the combination logic block 108.

The manner in which the on-board state generator 104 changes state canbe a function of internal programming 115, or to on-board sensors (i.e.light, temperature etc.) 106 or the state can be sequenced by the "p"106 remote control signals or it may correspond exactly to the state ofthe remote object 100 or any combination of the above.

The state of the on-board state generator can be used to activate orcontrol some effect or it may be exclusively reserved to select whatoptions are available to the remaining remote control signals. If theon-board state itself corresponds to a remote effect, that effect willbe unavoidably present regardless of which of the other "m" effects areavailable for that state. There will be "n" of these state dependenteffects shown as boxes 121, 122, and 123. Combination logic block, 125,determines which of the "n" possible effects are activated by the "n"operating state signals.

It is assumed here that knowledge of the state of the remote on-boardstate generator is known at the origin of the remote control signalseither through, for example, visual contact with the remote object orbecause the remote state is known or kept track of by the operatorcontrol remote effect. However, it is not implied that the operatornecessarily has remote control over the state of the on-board stategenerator. For instance, the state may be uniquely determined by thetemperature in the remove objects environment which may in the case ofmodel train layout be the same at the origin of the remote signals. Herethe operator of the remote signals "knows" what the state of theon-board state generator is and "knows" what effects each of the remotecontrol signals will have on the remote object. If the number of statesand remote options becomes large, an identical electronic stategenerator at the transmitter could be used to keep track of the on-boardelectronic state generator. No physical or electrical connection betweenthe two state generators is implied; only that the inputs to both stategenerators are designed to be the same.

As an example of how more effects can be generated than the total numberof remote control signals, consider the case where an operator has onlya total of three remote control signals on an electronic control system:signal #1, signal #2 and signal #3. Assume that there are a total offive unique states of the remote object and that the on-board stategenerator will correspond exactly to the same five unique states. Eachtime signal #1 is applied, the remote object and the on-board stategenerator sequences to the next state (this remote control signalcorresponds to the k signals shown in FIG. 1). Assume the operator hasdone this twice which establishes state #2 in the on-board stategenerator. In this state there are two remote control functionsavailable (this corresponds to the r or to the m signals in FIG. 1 sincethere is no select state generator in this example). If signal #2 isapplied a red light comes on; if signal #3 is applied a green lightcomes on. If the operator applied signal #2 and then signal #3 then hewould witness the red light coming on and then the green light comingon. If he did neither then the remote function would either be nothingat all or the state-dependent remote function designated for state #2.Assume he now applies signal #1 again and the on-board state generatorsequences to state #3. Here again the operator has two choices for theremaining remote control signals plus the remote function designated forthe state of the on-board state generator. From this example, it isapparent that there are ten remote control options for signals #1 and #2(two signals×five states) plus an additional five functions associatedwith the states of the on-board state generator(state dependentoptions); a total of fifteen. If the control signals alone had beenused, there would only be a total of three.

It is not implied that the control signals are exclusively digital,analog, or that each is limited to only one function. Even without theon-board state generator, each signal could control a vast number ofremote options. For instance, each signal might be a digital wordencoded on a carrier signal; here the remote features associated with itwould only be limited by the length of the word. However, the increasein the remote options available when an on-board state generator is usedis still multiplied by the number of states.

Also, the on-board state generator could select a number of remotefeatures that will respond to the control signals in an analog manner.An example would be a remote-control sound feature where the volumewould respond to the amplitude or perhaps the frequency of the controlsignal.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION Embodiment One

One embodiment of this invention for the control of AC powered modeltrains uses both positive and negative applied signals superimposed onthe AC track voltage as remote control signals. We use shortinterruptions of AC power to change the state of the on-board motorcontrol unit. We consider the state of the motor control unit to be thestate of the remote object (a model locomotive 50 in this case). Ouron-board electronic state generator will correspond in part to the stateof the motor control unit. However, since the old Lionel motor controlunits were mechanically operated, it is difficult to translate the stateof the motor control unit to an electrical signal that can be used togenerate the state of the on-board state generator. Also, the oldmechanical design has other problems that are annoying.

FIG. 16 illustrates a simple model railroad layout 10 that includes atrack 20. Track 20 is coupled to a power supply 30 over conductors 42.Power supply 30 is connectable via power cord 40 to a source of AC powersuch as an ordinary household electrical outlet. Power supply 30preferably includes both a conventional interruptible AC power sourcefor providing a track power signal, and DC signal generator circuitry asfurther described below with regard to FIG. 7. The model locomotive 50is positioned on the track.

In order to implement our remote option idea more easily, we havedeveloped a new electronic motor control unit that has become animportant part of this design. Our unit will sequence through the samefour states that correspond to the mechanical design when AC power isbriefly turned off (short power interrupt) but can also be "reset",which will establish the motor control unit in a known state when powerhas been off for more than three seconds (long power interrupt). We haveconstructed the unit to allow for easy access of internal electricalstates by connecting important signals to two electrical busses oneither side of the circuit board. Although there are a total of sixteensignals on the two busses, only four signals are used to define thestate of the unit. These are Q1, Q2, Reset and Clk; see FIG. 5. Theoutput logic values that distinguish the states of the unit are shown inFIG. 2A. The corresponding state diagram is shown in FIG. 2B. Q1 and Q2decode to the four reverse states, Clk is an output pulse thatcorresponds to the short power interrupt and reset is an output pulsethat corresponds to the "reset", or long power interrupt. The reset 201is shown as the forward (1,1) state, but it may be programmed by theuser for any state.

Actually we have developed two versions; one to control the state of DCor permanent magnet motors and the other to control the state of AC oruniversal motors. Circuit descriptions for both of these units are givenbelow. Circuit diagrams are shown in FIGS. 3 and 4. Although the twomotor control units control different kinds of motors, both have thesame states and bus connections to option modules, and both are poweredfrom AC.

The on-board electronic state generator that we used is shown in FIG. 5.There are a total of five states; including four motor control unitstates and an additional reset state. Four AND gates 501, 502, 503, 504are used to generate the four distinct motor control unit states fromthe Q1 505 and Q2 506 output signals. In order to establish the resetcondition as a unique state, a D flip-flop 507 is used to latch thereset pulse 508. When the motor control unit is turned on after a threesecond power down, the RS output 509 will be logic "1". When the motorcontrol unit is sequenced to the next state, the clk signal 510 willreturn the RS output to logic "0" and it will remain at that valuethrough all further short power interruptions. Since the user canprogram which motor control unit state will correspond to reset (longpower interrupt) the "RS" output is shown applied as "not RS" to thefour decode AND gates 501, 502, 503, 504. This way, no matter what motorcontrol unit state is selected to come up in reset, there will only beone state corresponding to reset in the on-board electronic stategenerator.

Since there is a total of five distinct on-board states and two controlsignals there is a possible ten remote control options. If the state ofthe on-board state generator is also used for remote control there arean additional five "state dependent" effects possible. In other words,if we use the state of the on-board state generator to actuate a remotefeature, that feature will also be present when any of the possibleremote functions for that state are actuated by the other two remotecontrol voltages (+DC or -DC).

Our signal detector is shown in FIG. 6. It will produce logic signalsacceptable to our decode logic that correspond to the positive andnegative DC superimposed remote control signals. A circuit descriptionis given below.

A system for transmitting both positive and negative DC control voltagesis shown in FIG. 7. Moving the switch arm 701 to "A" 702 or "B" 703 willproduce a positive or negative DC voltage respectively superimposed onthe AC track power 704.

FIGS. 8 and 9 show two possible embodiments of remote options for thisparticular system; one for a diesel and one for a steam engine. Thefirst column in each table shows the state of the on-board stategenerator, and the last column shows the possible remote control effectsfor each state. The two middle columns show the state of the applied DCremote control signals. A "0" means that no remote signal is applied, a"0-1" indicates that the remote effect is actuated when the signal isapplied, a "1-0" means that the remote effect is actuated when theremote signal is turned off, and a "0-1-0" means the remote effect isactuated and remains on even after the remote signal is removed.

An example of the last type of control voltage is for our remote controlbell shown in FIG. 11. When a momentary negative DC remote controlvoltage is applied in the forward state to the clock input 1100 of theD-latch 1102, the output 1101 will toggle between logic "1" or "0" andturn the bell sound effect on or off.

An example of a remote function responding to the continued presence ofa remote control signal is our horn sound generator shown in FIG. 11.When a positive DC remote control is signal is applied (0-1) in theforward, reverse or neutral before forward states, the horn sound effectwill be actuated as long as the remote control signal is applied.

An example of a remote function responding to removing the remotecontrol signal is the diesel motor start effect. For this option theuser applies a positive DC control signal (0-1) in the reset state whichstarts the sound effect of a large diesel motor turning over trying tostart. When he stops the signal (1-0), the motor then starts andcontinues running. Here two separate effects were generated by a singleremote control voltage.

Note that some of the remote control functions depend on whether or notthe engine is in slave mode. This is a feature for multiple unitconsists. On prototype railroads the first engine is the only one thathas a headlight on or the only one that will blow the horn or ring thebell. Other engines (slaves) in the consist are there only to providepower and perform no other functions. For our model diesel locomotiveswe provide a way of disconnecting some of these remote control optionsfor the slave units so only the first or master unit will respond to theplus and minus DC remote control signals. This can be done with a switchon the engine itself or slave mode can be entered and exited as a remoteoption.

An electrical schematic diagram for the AC train control system for thediesel example above is shown in FIG. 12. The electronic on-board stategenerator is the-same as FIG. 5 and is redrawn here to show itsconnections to other parts of the system.

The diesel locomotive (remote object) 1200 is connected to the AC powersupply 1202 and the plus and minus signal generator 1203 via the track.The three lines 1201, 1230, 1231 are drawn in to show that there arethree kinds on remote control signals available. Short power interrupts1201 from the AC power supply 1202 sequence the state of the motorcontrol unit 510 directly through the basic four states. Long powerinterrupts 1201 from the AC power supply 1201 reset the motor controlunit into a known state. This plus and minus DC remote control signalgenerator 1203 is shown connected to the AC power supply 1202 since itapplies the DC signals superimposed on the AC track voltage. The DCsignals are shown connected to the signal detector 1232 that puts themin a form usable by the system.

The on-board state generator FIG. 5 generates one and only one of fivestates at a time. The state signals 509, 512-15 are shown connected tosignal gating AND gates 1210-1224 along with the plus 1225 and minus1226 DC logic signals from the signal detector 1232. The output of eachAND gate is shown connected to remote functions such as headlights orbells or is shown not connected to anything if there is no remotefeature designated for that option.

As an example if the on-board state generator is in "reverse" the output514 of the AND gate 503 is logic "1". This signal is applied to bothinputs of AND gate 1219 which will in turn apply a logic one to theinput of AND gate 1240. If the locomotive is in the master mode then theoutput of master/slave latch 1241 is also logic "1" and the reverselight 1242 will light. This is an example of a state dependent effect.

If a positive DC voltage is applied to the track from the plus and minusDC signal generator 1203, then a logic "1" will also be generated on the+DC logic line 1226 and applied to AND gates 1211,1214,1217,1220,1223.This will produce a logic "1" at the output of AND gate 1220 the onlyone with two logic "l"s at its input. This signal is applied to OR gate1243 which produces a logic "1" at the input of the AND gate 1244. Ifthe locomotive is in the master mode the horn will blow.

Circuit Descriptions for the AC and DC Reversing Units (FIG. 3 and FIG.4, Respectively)

The two reversing units have much circuitry in common. In fact, circuititems 302-340 from FIG. 3 match exactly circuit items 402-440 from FIG.4. Numbers in parenthesis which follow a FIG. 3 drawing reference numberrefer to items on FIG. 4. The circuit description will be divided intothree sections: Common Circuitry, AC Specific Circuitry, and DC SpecificCircuitry.

Common Circuitry

Logic

The flip flops 338(438), 340(440) are wired as a two stage clocked ringcounter which can have four possible states, which correspond to thefour motor power states. They are (Q1,Q2): (1,1) forward, (0,1) neutralbefore reverse, (0,0) reverse, and (1,0) neutral before forward. Two ofthese four states are decoded into signals F (forward), and R (reverse)by 334(434) and 336(436), two of the four NAND gates. These two signals(F,R) are active low. That is when F is low and R is high then the"forward" power state is activated. The other two NAND gates 332(432)and 330(430) are used as a buffer in front of the clock to the flipflops (CLK) and as a buffer which delivers a reset (RES) command to theflip flops, respectively. These Schmitt buffers are needed to insure theflip flops will reliably be put into the expected state, since withoutthem, the CLK and RES signals would have rise times of severalmilliseconds(ms).

Power Supply

The components which comprise the negative VEE supply are: resistor310(410) diode 308(408) diode 312(412) capacitor 328(428) and rectifyingbridge 306(406). Resistor 310(410) is for current limiting. Zener diode308(408) works with resistor 310(410) to create a stable voltage at thecathode of diode 312(412). This voltage is passed through Diode 312(412)to charge capacitor 328(428), the power supply filter cap to form thenegative power supply (VEE). Diode 308(408) is used to isolate the powersupply to prevent capacitor 328(428) from discharging when the input ACis returned to ground. One additional significant discharge path forcapacitor 328(428) exists when the AC input is returned to zero wheneither F or R are low. This is from the current flowing into whicheverNAND gate (334 or 336) is in the low state. This is the purpose ofdisconnect transistor 350(450) to stop this discharge of capacitor 328.The disconnect of all power drains when AC power is interrupted isextremely important as it allows VCC to remain constant independent ofstate. Without this feature it would be impossible to control the timingaccuracy of the reset period much better than 3011 seconds. With thisdisconnect the reset timing is controlled to 1.5-3 seconds. When ACinput power is applied (across AC and ACG) the base of transistor350(450) is pulled low saturating it. This applies a ground connectionto the power control section. When AC is removed, the base of transistor350(450) (terminal strip connection "D") is pulled to ground by resistor354(454) thus turning off transistor 350(450) and removing the loads onthe NAND gates as well as shutting down the power control section.

Timing Circuitry

The purpose of the timing circuitry is to produce the proper RES and CLKsignals in response to interruptions in AC power.

Reset Circuitry

Whenever AC power is interrupted the anode of diode 308(408) rises fromits usual -4.3 V to ground. When the AC is applied, the anode of diode314(414) is at -3.6 V and capacitor 324(424) is charged to -3.6 V aswell, the +side of capacitor 324(424) (and the input to the "reset" NANDgate 330(430)) is pulled to ground by resistor 322(422). When AC isinterrupted diode 314(414) removes the loading of the input leavingcapacitor 324(424) to be discharged by resistor sum 322(422)+324(426).With AC interruptions of less than 3 seconds capacitor 324(424)discharges to less than 1/2 VEE. Thus, when AC is reapplied, the inputto the "reset" NAND 330(430) does not fall low enough to cause alow-to-high transition on the RES line. Therefore, no reset will occur.However, if the AC is interrupted for longer than 3 seconds, capacitor324(424) discharges to less than 1/2 VEE and RES will go through alow-high-low transition, resetting the flip flops to their correctstate. At power up, after some time (say, 30 seconds), 324(424) willhave completely discharged. But, since VEE is still up {328(428) chargedto -3.6 V} RES will stay low (-3.6 V) all the while. Thus, at power up,RES goes low-high-low resetting the flip flops. At power up, after along time (more than 1 hour), VEE will be at ground as well. At powerup, both VEE and the input to the "reset" NAND jump to -3.6 V and theRES line jumps high. The flip flop Set and Reset lines are "levelsensitive and will asynchronously operate whenever the set(reset) linesare high (0 V). Thus, at initial power up the motor control units will"reset". The "reset" time is determined by time constant 324×(326+322){or for the DC motor control unit, 424×(426+422)}. This is completelydominated by 326×324 (426×424). Time constant 322×324 (422×424) isselected only to be long enough to ensure that RES stays high(0 V) longenough to effect a proper resetting of the flip flops. It would appearthat you could get by with leaving out either 316(416) or 314(414) (butnot both). However they were both included to stabilize the reset timingagainst radically different AC power settings before and after a resetinterruption.

Clock Circuitry

Whenever AC power has been on for some time the anode of 308(408) is at-4.3 V and the anode of 316(416) has charged to -3.6 V (a logic low).The output of the "clock" NAND is therefore high. Since flip flops338(438) and 340(440) are positive-edge triggered, nothing in particularhappens yet. When the AC power is interrupted for longer than about 1/4second, the anode of 316(416) changes far enough toward ground to causethe output of the "clock" NAND 332(432) gate to go from high to low.When power is re-applied this NAND gate output goes low to high andclocks the flip flops. If the AC power has been off longer than 3seconds a "reset" occurs as described above.

AC Specific Circuitry

Input Rectifiers

There are two rectifiers: one is a full wave bridge 306 to power thelogic, disconnect circuitry and provide the input signals to the timingcircuitry 306; the other is also a full wave bridge made up of diodes302,304 and two diodes in the bridge 306 to provide the return path toground. This rectifier charges 360 to provide the negative supply foroperating the two relays 356 and 358. The value of this voltage isapproximately (-Vpeak+0.7 V). It is significant to note that the use ofa full-wave bridge 360 allows proper operation from either AC or DCtrack power.

Disconnect Circuitry

In the AC unit, the disconnect circuitry consists of 350,346,344, and342. When AC power is applied a negatively pulsating voltage is appliedto the base of transistor 350 through current limiting resistor 346.This saturates 350, applying a ground connection to 348 and thusenabling the motor control section. Capacitor 342 serves to filter the120 Hz pulsating DC so that the relays don't chatter. Resistor 344exists to discharge 342 and turn off 350 when AC power is removed.

Relays and Relay Drive Circuitry

With 350 on, DC power will be routed through either 354 or 352 (orneither) depending on the logic state of lines F and R. If F is locurrent flows through 354. If R is low current flows through 352. If Fand R are both high then neither 354 or 352 conducts. The logic signalvoltage on F [R] works with 348 forming a current source which is passedthrough 354 [352] energizing relay coil 358 [356].

The current source comprises, in the preferred embodiment, a biassource, a DC power supply and a current-source transistor. Thecurrent-source transistor, corresponding to transistor 354 (352) in FIG.3, has a collector (output) coupled to the relay coil 358 (356). Theemitter (input) of transistor 354 (352) is coupled through a resistiveelement 348 and transistor 350 to the DC power supply 306,342,346. Thebase (control) terminal of transistor 354 (352) is coupled to the biassource, i.e. Schmitt trigger gates 334 (336), respectively. The Schmitttrigger gates, when ON or active-low, sink current (toward VEE), therebybiasing transistor 354 (352) ON, so that the transistor 354 (352)provides a DC current to the relay coil.

More specifically, the track power is provided to diodes 302, 304 andbridge 306, to provide a negative pulsating DC voltage, which isconnected to and filtered by capacitor 360. This negative supply voltageis connected to the common node of relay coils 356, 358. It may be notedthat the "+" terminal of bridge 306 is connected to ground. Thus, allvoltages in FIG. 3 are negative.

One or the other of the coils are energized by a current source asfollows. One of the Schmitt trigger outputs R or F is low at a time. Forexample, F low provides bias voltage to the base transistor 354. Theemitter of 354 is connected to resistor 348 which, in turn, is connectedthrough a saturated transistor switch 350 to ground. Transistor 350remains saturated whenever AC track power is applied. Therefore, thecollector of 350 remains at a saturation voltage below ground. Theemitter of 354, when F is low, is a V_(BE) above F. Therefore, thevoltage across resistor 348 is fixed, so the current through it and intothe emitter 354 and out to the relay coil 358 is constant. This circuitthus forms an electronic current source that is independent of loadcharacteristics at the relay coil and the supply voltage at capacitor360.

The motor field winding 370 is wired to ACG. It is the armature 362whose current is change by the relays. The field winding and armaturewinding are connected in series.

DC Specific Circuitry

Input Rectifiers

There are two rectifiers: one is a full wave bridge 406 to power thepower transistors and motor; the other is also a full wave bridge madeup of diodes 402,404 and two diodes in the bridge 406 to provide thereturn path to ground. The latter rectifier supplies power for thelogic, part of the disconnect circuitry, and provides the input signalsto the timing circuitry. Because we use full wave rectifiers this unitcan be operated from either DC or AC track power.

Disconnect and Low-Voltage Control Circuitry

The disconnect circuitry consists of 450,456,466, and456,454,458,462,494,464, and 460. The best way to understand thedisconnect circuitry is to first imagine 456,466,454,458,442,494, and464 are not present in the circuit. Then you would notice that wheneverAC power is applied the base of 350 is pulled low through 460 and462+456 thus saturating 450 and applying power to the power controlsection. You will also note that whenever the input AC power drops belowabout 2.1 V peak 450 will turn off. This happens 120 times per secondwhen power is applied independent of the AC amplitude, (so long as theAC power is above 2.1 V peak). At higher voltage settings this effect isnot even noticeable. This is all there would be to the disconnectcircuitry were it not for one serious problem. The AC power supplies fortoy trains often start at six to nine volts and increase to twenty. Mostof the DC motors that are easily available start at two to three voltsand are at peak power at twelve. In order to have locomotives equippedwith DC motors start out at a low velocity when the AC power supply isjust turned on, a way must be provided to keep the full power from beingapplied at lower AC amplitudes. This is the idea behind circuit 454. 454operates as a voltage divider with 456 keeping 450 off whenever theinput AC power is below approximately 1.4 V+(0.7 V)×(RATIO). Where,RATIO=(456+454)/454. The purpose of 494,460,464, and 466 is to provide atiming delay between when power is available to the power controlsection and when it is actually turned on. The voltage at the emitter of466 becomes large enough to turn on 450 only after 464 has been chargedthrough 462. Thus, as the ratio of 454/456 is varied, the duty cycle ofthe applied full-wave rectified power is varied for a given transformersetting. 460 insures that 464 is not discharged as the power waveformpasses over its peak. Otherwise, 450 would turn off before the end ofthe power cycle. When the end of the power cycle is reached, 464 must berapidly discharged. This is achieved by 466. The instantaneous voltageon the base of 466 can never fall below -4.3 V wince it is clamped byZener diode 408. As the instantaneous input voltage rises to 0 V diodes402 and 404 turn off and a path for 466's base current is provided by494. This turns on 466 which in turn discharges 464. With 464 discharged450/60 now shuts off. If 464 were not discharged at the end of each halfpower cycle it would not provide the expected delay in applying the nextpower half cycle.

A significant advantage of this type of drive is that the DC motorreceives "pulse drive" at lower power settings. This is an especiallyattractive way to start up a DC motor. Its performance is steady andcontrollable. This performs well, but the drive turning 450 on and offis too gradual and 450 spends far too much time in its active region(remember it is being cycled on and off at a 120 Hz rate). Without 452and 458, 450 would overheat. 452 is connected to 450 in such a way as toform a "discrete SCR". 458 provides the hold current to keep 452 on onceit has been triggered from the AC power input. Also the resistor ratio454/458 plays an important role in determining the loop gain around450-452 and thus the exact turn on voltage for 452. The exact expressionfor turn-on is complicated by the presence of 448 and 446. A smoothpulse driven turn-on beginning at the lowest obtainable transformervoltages (-6 Vpeak) can readily be obtained.

Power Control Circuitry

When logic signal F[R] is low, base current is drawn through resistor442[444] saturating transistor 446[448] and thus applying a groundconnection through resistors 468[470] and 474[472] to the bases oftransistors 486[490] and 476[482] respectively. This connection turns ontransistors 486[490] and 476[482] which in turn causes heavy conductionof 484[488] and 478[480] respectively. Under this condition, currentflows into motor terminal M2[M1], through the motor 492 (or whatever DCload device is desired), and out terminal M1[M2] and is returned to thenegative terminal of 406 through 484[488].

By rereading the last paragraph using the terms in brackets one noticesthat the current that flows through the motor connected across terminalsM1-M2 will have its current reversed when logic signal R is low insteadof F. If signals F and R are both high then no power is applied to themotor. This is the case for either of the two "neutral" settings. Thecondition F and R both low would be disastrous. Fortunately, this cannotoccur as long as NAND gates 434 or 436 are not defective.

It is interesting to note that the transistor pair 482-480 (or 476-478,486-484, 490-488) operate as a compound "super" pnp transistor.

Plus and Minus DC Signal Detectors

The DC signal detectors along with our DC power supply for all of ouron-board electronics is shown in FIG. 6. AC track power applied between`B` 620 and `A` 621 is rectified by the bridge circuit made up by diodes601-604. A dropping resistor 606 along with a Zener diode 605 produce anegative supply at `C` 623 equal to Vz. The capacitor 607 is used as apower supply filter.

The RC networks made up of 608 and 610 for circuit 1 and 613 and 615 forcircuit 2 are low pass filters that prevent the sixty cycle line voltageat 620 and 621 from turning on either transistor 609 or transistor 614.If a small DC (>0.7 volts) is applied at 620 and 621 in addition to theline current the base emitter junction of either 609 or 614 will beturned on depending on the polarity. If `A` 621 is DC positive withrespect to `B` 620 then transistor 609 will be on and collector currentwill flow as long as `C` 623 is more negative then `A` 621. This willoccur during the entire positive cycle of `A` 621 when diodes 603 and604 in the bridge rectifier are forward biased. In addition collectorcurrent will flow during part of the negative cycle until 604 is backbiased by the a voltage equal to Vz of the power supply Zener 605. As`A` 621 continues more negative diode 619 prevents the forward biasedbase-collector junction of transistor 609 from taking current form theZener supply. Circuit 2 works in the same way if `B` 620 is DC positivewith respect to `A` 621.

Note that with capacitor 612 placed across 611 the voltage at `D` 624will charge to Vsat of transistor 609 below `B` 620 and diode 619 willconduct only during positive half cycles, assuming the time constant ofthe low pass filters is much greater then the period of the applied ACpower.

Applying a positive DC remote control signal at `A` with respect to `B`results in a logic `1` at `D` 624 (approximately zero volts with respectto power supply ground 625). Applying a negative DC remote controlsignal at `A` with respect to `B` results in a logic `1` at `E` 626(approximately zero volts with respect to power supply ground 625). Ifno DC signal is applied, the voltage at `D` 624 or `E` 626 is a logic`0` (-Vz with respect to power supply ground 625).

EMBODIMENT TWO

This embodiment also employs the state of the reverse unit and the fivestat electronic state generator described in the first embodiment.However, instead of using "-DC" as a remote control signal, applied ACpower supply voltage in excess of a predetermined value is used as anadditional remote control signal. This system will be more limited thanthe first but will be easier for the Lionel user since it will notrequire him to purchase or construct a -DC generator. The maindisadvantage of this approach is that the applied "AC" power supplyvoltage also controls the speed of the locomotive which makes itdifficult to use a particular value of AC power voltage as a remotecontrol signal when the locomotive is in forward or reverse. However, inthe three other states of "neutral before forward", "neutral beforereverse" and "reset (in neutral)" AC power voltage as a remote controlsignal is useful.

One particular approach is shown in FIG. 13. The peak detector 1301responds to income AC power by producing a DC voltage, 1302,proportional to the peak AC power supply voltage 1314. The peak detectorcontains electronic filters to insure that motor or other electricalnoise does not get detected and also produces a smooth DC voltage withlittle AC ripple. Capacitor, 1309, is used to block DC remote controlvoltages on the track from interfering with the detection of AC powersupply voltage. Comparator, 1303, compares peak voltage, 1302, with DCreference source, 1315 and responds with logic signal 1304. The selectstate generator, responds with one of "m" effect control signals bycounting the number of times signal, 1304, is applied. If peak AC powervoltage is applied "j" times such that DC signal, 1302, exceedsreference, 1315, each time, then select state generator will respondwith the "j"th effect control signal. The electronic state generator isa ring counter and will return to its first state if it is in the "m"thstate and one more signal, 1304, is applied. Signal, 1305, from theelectronic state generator, will also reset the select state generator,1306, to its first state when any change in the electronic stategenerator occurs.

The "+DC" detector, 1308, responds to applied DC voltage that issuperimposed on the AC power supply voltage, 1314, in the same manner asdetector, 1232, in FIG. 12 except only the "+DC" logic signal, 1226, isgenerated.

One effect for Lionel model trains that is particularly well suited tothis embodiment is shown in FIG. 14. Lionel produced an automatic modeltrain coupler that used a solenoid in the coupler assemble to open thecoupler knuckle when power was applied to a special sliding shoe from aspecial operating track section on the layout. In some engines, Lionelused the DC remote control signal to operate the coupler anywhere on thelayout but it eliminated using this DC remote control signal for aremote horn. Also, when the engines had both front and rear couplers,both would open when the DC remote control signal was applied. Sincepower for the couplers came from the engine, when the engine was movingslowly there was often not enough voltage present on the track toactuate the coupler solenoid.

Our invention eliminates these problems. When the appropriate effectcontrol signal, 1321, is applied the rear coupler arming latch, 1403, orfront coupler arming latch, 1404, can be set from AND gates, 1401, or1402, if the engine is "neutral before forward", 515, or "neutral beforereverse", 513, respectively. Once the coupler arming latches are set,they will remain in that state until they receive a reset signal, 1411,or 1412. If a "+DC" logic signal is applied, the selected switch, 1407,or switch, 1408, 1 will close and apply voltage from the coupler supplypower supply, 1409, to the connected coupler coil. The coupler arminglatch resets 1411 and 1412 are generated from the output of AND gates,1405, and 1406, respectively.

The coupler power supply, 1416, contains capacitors to store energy fromthe peak applied AC power supply voltage. This will provide extra powerfor the couplers when the engine is moving slowly and there is notsufficient voltage on the track. It is convenient that the coupler powersupply will charge at the same time that the coupler latches are armedsince a high DC voltage is needed to select this effect in the firstplace.

PREFERRED EMBODIMENT

Referring to FIG. 15, this embodiment also employs the state of thereverse unit and the five state electronic state generator described inthe first embodiment, also using "-DC" as a remote control signal.

This system will be similar to the first embodiment but will includeseveral extensions. A block diagram for this embodiment is shown in FIG.15. This system shows three primary control inputs: 1201, the AC powerwhich goes to FIG. 5, the on-board state generator, 1230 which is thepresence of a small +DC signal superimposed on the basic AC power, and1231 which is the presence of a small -DC signal superimposed on thebasic AC power. As discussed earlier, the AC power signal is also usedby the remote object itself as a source of energy to operate themotor(s) in the remote object (a toy locomotive.)

The purpose of signal detector 1232 is to extract the information thatthe +DC (or -DC) signals were superimposed on the AC power and produce alogic control signal at the output which is of a proper format as to beused by the remainder of the system. In this case we envision using CMOSlogic. Line 1225 is the -DC logic output control line (called "select"signal) which corresponds to signal 1230 being active. Line 1226 is the+DC logic output control line (called "operate" signal or effectoperating signal) which corresponds to signal 1231 being active. In thissystem, it would not make sense for signals 1230 and 1231 to be activeat the same time.

Similar to the previous two embodiments, this system utilizes fivecontrol lines 509, 512-515 from the on-board electronic state generatorFIG. 5 in combination with m "effect control signals" 107 which arecombined at combination logic block 108 with an effect operating signal1226 to activate a large number of remote-control effects 1505-1514,etc. A new feature here is the presence of 110, the select stategenerator. This block is a resettable counter plus decode logic whichtakes the single logic signal ("select") from signal detector 1232 andoutputs a number, m (larger than one) of effect control signals 107 byusing various aspects of the past history of applied "select" signals1225 to decide which of the m effect control signals 107 would be activeat a time.

This system contains yet one further aspect by which the organizationcan be improved and the sheer number of possible effects can beextended: this is by using one of the m control positions of 107irrespective of the condition of the five operating state signals, aswhat might be called "page advance". This is shown as effect 1512. When1512 has been enabled via the correct effect control signal 107 andoperated via the "operate" signal then the page select state generatorwill advance to its next state. Page select lines 1507 are fed back tothe combination logic block 108 as to direct what would have been thesame set of effects, to be chosen from a different set (page). Thispermits 5× m (five times m) effects for each page (state) of the pageselect state generator. Rather than simply generating huge numbers ofpossible controllable effects, this feature provides an excellent way toorganize the effects into meaningful groups.

The rest of FIG. 15 consists of several "special" effects which need tobe described. By "special", we mean to imply "beyond the obvious set oftoy locomotive remote control effects--perhaps, such as "bell", "horn","uncoupler", "overhead blinking light", etc. These common effects arealluded to be effects blocks 1513, 1514 . . . and so forth. The first ofthese "special" effects to be described is "sequence", 1515. The"sequence" option is used in the following way: when the "sequence"option has been selected by the proper combination of 107, 509, 512-515,then "sequence enable" signal 1505 is activated. What this does is setup the on-board electronic state generator FIG. 5 to no longer respondto power interruptions on AC power signal 1201 with state changes whichwould have sequenced the locomotive through its normal directionchanges. Instead of responding to 1201, the on-board electronic stategenerator will respond to changes is the "sequence" signal 1506 comingfrom the sequence effect 1515. The "sequence" signal 1506 will beactivated every time the "operate" signal 1226 is activated--so long asthe "sequence" effect is activated (sequence enable, 1505 activated.)

When properly "selected" via control signals 107, 509, 512-515 effect1511 called "reversal" will reverse the direction that the locomotiveconsiders to be its forward direction every time that the "operate"signal 1226 is activated.

When properly "selected" via control signals 107, 509, 512-515 effect1510 called "master/slave (latch)" will alternately put the locomotiveinto a "slave" status or into a "master" status every time that the"operate" signal 1226 is activated. In "master" status the locomotiveperforms in its normal manner described in this embodiment. However,when the locomotive is in "slave" status, none of the "obvious" effects(such as bells, lights, horns) that the locomotive might display areoperable. The locomotive will still respond to direction changes via ACpower interrupts, the "sequence" effect, the "reversal" effect, the"latch" effect and the "Disconnect" effect as well as the "master/slave"effect. That is to say, by re-operating the "master/slave" effect thelocomotive can be restored to "master" status.

When properly "selected" via control signals 107, 509, 512-515 effect1509 called "lock" will alternately put the locomotive into a conditionwhere the direction of the locomotive cannot be changed via the usualpower interruptions on signal 1201 ("locked" mode) and a condition wherethe locomotive responds in its usual manner to power interruptions onsignal 1201 ("normal" or "unlocked" mode). In the "locked" mode thelocomotive will still respond to direction changes via the "sequence"effect 1505 & 1506 if they are properly selected and operated. Theimportant feature here is that whatever direction the locomotive wasgoing (forward, neutral, reverse) prior to the locomotive being put int"lock" mode, it will remain locked into that direction until it ischanged via the "sequence" effect or it is taken out of "lock" mode andsequenced in the normal fashion via AC power interruptions on signal1201.

When properly "selected" via control signals 107, 509, 512-515 effect1508 called "disconnect" will alternately put the locomotive into acondition where the locomotive behaves as if it were in "slave" withregard to its "obvious" effects and the motor power is forced into anoff or "disconnected" status (this is called the "disconnected" mode)and into a condition where the locomotive operates in its usual manner.

We claim our invention to be:
 1. A reversing motor control circuit fordriving a motor in a remote object on a track, the circuitcomprising:input means for receiving a track power signal from thetrack; state means for indicating a present state that is one of apredetermined series of states including a forward state, a neutralstate and a reverse state, the state means having a clock input forclocking the state means to indicate the next one of the series ofstates as the present state; power control means coupled to the inputmeans for controllably coupling the track power signal to the motor soas to control the motor according to the present state of the statemeans; a reset timing means for resetting the state means to a selectedone of the series of states upon completion of a predetermined resetperiod; and a clocking timing means for clocking the state means to thenext state upon completion of a predetermined clocking period; the resettiming means and the clocking timing means each coupled to the inputmeans to begin the reset period and begin the clocking period responsiveto an interruption in the track power signal, whereby operation of thestate means is controlled by interrupting the track power signal.
 2. Areversing motor control circuit according to claim 1 wherein the resetperiod is within a range of approximately 1.5 to 11 seconds.
 3. Areversing motor control circuit according to claim 1 wherein the resetperiod is greater than approximately 3 seconds.
 4. A reversing motorcontrol circuit according to claim 1 wherein the clocking period isgreater than approximately 1/4 second.
 5. A reversing motor controlcircuit according to claim 1 wherein the reset timing means and thestate means are arranged so as to reset the state means to the neutralstate upon completion of the reset period.
 6. A reversing motor controlcircuit according to claim 1 further comprising means for programmingthe motor control circuit to reset to any desired one of the series ofstates in response to an interruption in the track power signal having aduration in excess of approximately the reset period.
 7. A reversingmotor control circuit according to claim 1 wherein the programming meansincludes means for remotely programming the motor control circuit inresponse to a remote control signal.
 8. A reversing motor controlcircuit according to claim 1 further comprising means for resetting themotor control circuit to the selected state upon initial power-up of thecircuit.
 9. A reversing motor control circuit according to claim 1further comprising means for minimizing loading effects on the resettiming means when the track power signal is interrupted so that thereset period is controllable to a range of approximately 1.5 to 11seconds.
 10. A model train on-board control system comprising:anelectronic reversing motor control circuit having a predetermined seriesof states including a forward state, a reverse state, and a neutralstate for controllably coupling a track power signal to a motor; anon-board electronic state generator having at least one more state thanthe motor control unit, one of the state generator states being a uniquereset state, and the other state generator states including states thatcorrespond to the respective states of the motor control unit; and meansfor resetting the state generator to the reset state responsive to aninterruption in the track power signal of at least a predeterminedduration, independently of the state of the motor control circuit.
 11. Amethod of initializing a motorized remote object positioned on a track,the method comprising the steps of:providing a reversing motor controlcircuit in the remote object for driving the motor; providing anon-board electronic state generator in the remote object for indirectlycontrolling predetermined effects; resetting the motor control circuitto a neutral state so that the remote object remains at rest on thetrack; responsive to the neutral state of the motor control circuit,enabling the state generator to receive remote control signals; andtransmitting at least one remote control signal to the remote object soas to initialize the state generator while the motor control circuit isin the neutral state.
 12. A reversing motor control circuit for use in amodel train system having a track coupled to an interruptible electricpower source for providing a track power signal, the circuitcomprising:input means for receiving the track power signal; a statemachine for indicating a present state that is one of a predeterminedsequential series of states including a forward state, a neutral stateand a reverse state, the state machine having a clock input forreceiving a clocking signal to change the present state to a next one ofthe series of states; clocking means coupled to the input means and tothe clock input for providing the clocking signal to change the statemachine state to a next one of the series of states in response to aninterruption of the track power signal having a duration of at least apredetermined clocking period; power control means for controllablycoupling the input means to a motor and responsive to the state of thestate machine for driving the motor in a forward direction when thepresent state is the forward state and for driving the motor in areverse direction when the present state is the reverse state andmaintaining the motor in a non-moving state when the present state is inthe neutral state; and reset means coupled to the input means and to thestate machine for resetting the state machine directly to the neutralstate responsive to an interruption of the track power signal having aduration of at least a predetermined reset period that is longer thanthe clocking period.
 13. A reversing motor control circuit according toclaim 12 wherein the reset period is within a range of approximately 1.5to 11 seconds.
 14. A reversing motor control circuit according to claim12 wherein the reset period is greater than approximately 3 seconds. 15.A reversing motor control circuit according to claim 12 wherein theclocking period is greater than approximately 1/4 second.
 16. Areversing motor control circuit according to claim 12 further comprisingmeans for programming the state machine so as to reset to any desiredone of the series of states in response to an interruption in the trackpower signal having a duration in excess of approximately the resetperiod.
 17. A reversing motor control circuit according to claim 16wherein the programming means includes means for remotely programmingthe state machine in response to a remote control signal.
 18. Areversing motor control circuit according to claim 12 further comprisingmeans for resetting the state machine to the selected state upon initialpower-up of the circuit.
 19. A reversing motor control circuit accordingto claim 12 further comprising means for minimizing loading effects onthe reset means while the track power signal is interrupted, so that thereset period is controllable to a range of approximately 1.5 to 11seconds.
 20. A model train on-board control system comprising:anon-board electronic state generator having a predetermined series ofstates including a forward state, a reverse state, and a neutral statefor controllably coupling a track power signal to a motor, and furtherhaving an additional, unique reset state; and means for resetting thestate generator to the reset state responsive to an interruption in thetrack power signal having a duration of at least a predetermined resetperiod.